Diminution (Part IV)
Here the diminutions have been removed. To simplify it further any repeated notes have not been included. This example makes clear the implication of the previous one, that these first few lines of the nursery rhyme comprises:

a consonant skip from the initial C to G (bars 1-2)

a neighbour note that prolongs the G (bars 2-4)

a descending fifth progression from G to C (bars 4-8)

This is the essence of a Schenkerian analysis - it shows how various harmonies are prolonged by a two-voice contrapuntal structure (top line plus bass) that follows many of the rules of species counterpoint.

A proper Schenkerian analysis is notated rather more elegantly than this (as is explained in How to Do a Schenkerian Analysis) but the basic principles are clear even from this example. In this case, it reveals something that we would probably know already - that a familiar tune lurks just beneath the surface. In a longer and more complex work they may be many more layers than the two shown here - a Schenkerian analysis helps us understand what holds the music together and perhaps how we (unconciously) make sense of it as listeners.

It may seem from this example that Schenkerian analysis is about peeling back layers, reducing the music to a skeleton structure and this is indeed how it is often discussed.

The Schenkerian analytical model is, however, much more interesting and subtle than this. Schenker tries to explain how complex musical surfaces can be understood as decorating, prolonging, or even delaying the completion of simple progressions. This is more fully explained in the next section on the fundamental structure.

For the sake of clarity, this analysis has concentrated on the top line of "Twinkle, Twinkle", but the bass line also is includes several diminutions.

In the first bar, the harmonic unit of I (C) is prolonged by a consonant skip to E, and in the third and fourth bars, an arpeggiation connects IV and I (if you think there is something odd about this arpeggiation you might want to have a look at bass progressions).